text: Anthropogenic climate change is estimated to impact the marine environment in a variety of ways. In the arctic and subarctic environments where a vast majority of Calanus spp. reside, melting ice caps and timing of the spring phytoplankton bloom could have implications for copepod density, distribution and timing of return from overwintering. A phytoplankton bloom occurs in the spring in arctic and subarctic environments when sea ice melts, allowing an increase in light to penetrate deeper into the water column, thus supporting photosynthesis. An input of freshwater from the sea ice melting increases the stratification of the ocean in the summertime. Stratification leaves nutrient-rich water on the bottom and nutrient-poor water on the top due to an increase in freshwater from the ice. However, in the wintertime, this region of the world experiences an increase in storms that bring nutrient-rich waters into the more nutrient-poor surface waters. Climate change alters the timing of the spring bloom by promoting an earlier or later ice melt. Warmer waters could lead to weaker stratification, meaning the density differences between the first and second layer of the ocean are increasing due to an increased flux of freshwater from ice melt. Typically, the amount of total annual primary productivity in the Bering Sea associated with a spring bloom is approximately 10–65%, however warmer waters could impact the amount of primary production occurring.